E85: Is It Time You Made The Move?

For the majority of us import sports car enthusiasts, 98RON fuel provided at the local pump serves its purpose quite well. Whilst not exactly cheap these days, it is at least abundant and has a decent octane rating. But as with most things in life, there will always be something better out there to tempt you.

If you surf the forums as much as Jay and I do, you would have stumbled across threads praising the benefits of the E85 ethanol and fuel blend. Yanks have been using it for years and it’s finally becoming readily available in Australia via the United and Caltex petrol stations.

There’s a plethora of good reasons to make the move from your ordinary pump fuel to the sweet allure of E85. Not just because it smells heavenly, but there’s actually some hefty performance benefits too which I’ll get into below.

Even despite my lengthy forum trawling and research, there were still so many “what if’s” that haunted my daily thoughts. If it wasn’t for Jay incessantly reassuring me (and telling me to harden up), I probably wouldn’t have embarked down this path. Not to mention the promise of extra kilowatts helped too.

So if you’re like me who is bit of a skeptic and worry about impossible scenarios, then hopefully this write-up will help make your mind up. I remember asking myself these very same questions not so long ago…

Do it… just do it.

What is E85 and why does it smell so damn good?

Ethanol is an alcohol based liquid produced primarily from sugar cane and corn – combine it with some normal bowser fuel and you get your E85.

The “85” represents the 85% ethanol and 15% fuel mixture content and is probably the most desirable blend for us who want the most performance benefits (E10 and E70 is also available).

You might be thinking why don’t we just use 100% ethanol? Well the 15% fuel is actually to assist with atomisation and starting especially in colder weather conditions as ethanol has a much higher flash point (temperature where it can ignite). You don’t want to be cranking forever and burning out your starter motor on a cold a winters day that’s for sure.

As for the smell? Well that sweet exhaust smell is because you’re burning what is essentially sucrose (sugar) from sugar cane and corn! (Doesn’t mean you can sit by your exhaust and sniff it in though).

Something like that…

What’s the availability like?

United were the first petrol stations to bring this heavenly jungle juice to our shores and Caltex soon followed with their “E-Flex” E70 blend. That’s it, a massive total of two petrol companies with their own limited selection of stations offering E70/E85. This means availability can be a tad scarce especially if you’re not based near the state capital cities.

To give you an indication, there are 7 United and 9 Caltex stations within a 50km radius of the Sydney CBD offering E70/E85… which actually isn’t too bad. But if you’re up towards Newcastle, Goulburn or Nowra you might find yourself driving a fair while to get your next corn syrup fill.

On the upside though, with the increasing popularity and demand of E85, United and Caltex are listening and making more and more stations offer this great blend (Spam their Facebook pages please).

Also sucks if you live in the hills area…

Will I get more power?

Hell yeah! But filling up with E85 on your next servo trip isn’t magically going to give you another 20kW, chances are it’ll make your car (lean) misfire like mad and run horribly… and that’s being optimistic.

Get your ECU tuned for E85 by a workshop or yourself (if you have the skills) and yes, that will yield more power. By pumping in more timing into the tune and optimising the AFR to the new ratios, this is where those precious kilowatts and newton metres are unlocked.

Expect an increase of 20% at minimum but the real beauty is the extra torque everywhere on the power curve. Even with my puny stock T28 turbo setup, the car feels much stronger at all rpm’s and I didn’t need to give it as much gas as before to get it going. Hell, even boost in 6th gear was impressive now! (great when cruising to Wakefield)

When we finally got around to putting her on the dyno to measure the exact gains, Pearl made an impressive 224kW – that’s an increase of 27kW!(dyno sheet)

Any other benefits?

Wasn’t more power a good enough reason already?

Well if you really need more convincing, then consider these:

– Knock resistance. Imagine how much your engine is going to love you with E85 running through its’ veins minimizing the risk in blowing up your engine when running too lean or running too much timing. Instead of pinging it’s head off you will just lose power instead… #truestory.

– Stay cool. Ethanol burns at a lower temperature…… Less heat equates to less stress on the engine and it’s components resulting in better longevity. And by reducing EGTs you potentially could run the mixtures a little leaner than fuel and still keep your car happy!
I’m still not used to feeling cool air coming out of the exhaust after the car has warmed up though, that’s just plain spooky.

– Stay smooth. Ethanol cleans out all the gunk and dirt that’s built up after all those years of dirty fuel. It’s not uncommon to see dirty fuel pump socks, fuel filters and gunk on your injectors. A cleaner fuel system ensures she’s purring smoothly (I can feel that some of the harshness has somewhat disappeared, she purrs smoothly now).

– Stay clean. Now let’s not forget about mother nature, she’s pretty important. Considering ethanol is produced from a sustainably renewable resource (corn/sugar cane), that’s straight up brownie points with the tree hugging crowd and gives the U.S much less cause to invade Iraq. Not to mention more burnt ethanol means less burnt fuel meaning lower emissions, double whammy!

Not that you really need to know the downsides of E85 since you’re now converted… but if you must:

– Fuel Economy. It’s going to suck. If your car sucked before, it’s going to suck even more (literally) with E85. Blame the need of a continual high flow of E85 to the engine. That said though, I have managed 350kms+ on a full E85 tank! Considering I used to get about 450kms+ on pump 98 that’s not so bad, but it does all depends on your tuner of course to optimize your fuel maps.
That said though the cheaper price of E85 compared to 98 roughly offsets the mileage deficit anyway! ($1.20L vs $1.60+L) – it’s nearly a false economy.

– Availability. Knowing you can’t just rock up at your local servo for your next fill can be slightly infuriating. This just means more careful planning when going on trips and plenty of jerry cans when heading down to the track!

– Gunk. With the awesome cleaning properties of ethanol, you will need to replace your fuel filter regularly to ensure it won’t get clogged with dirt and residue from within your fuel system. Additionally, it is recommended to run some ethanol cleaner every few tanks to remove more gunk from injectors which can cause serious problems.

– Water. Ethanol by nature likes to suck water from the moisture in the air. Many people on forums (including myself) have been concerned about leaving ethanol in your fuel tank or jerry cans for an extended period of time (weeks) as it may collect water. And as we all know water into your engine is a very bad thing. The consensus is that it’s not as bad as it seems, but it’s always something in the back of your mind as a warning.

Sold! What do I need?

Bigger injectors and fuel pump: these are a necessity in order to deliver the new fuel blend into your engine. Even though most new ones are, ensure they are e85 compatible. Here’s some help installing it on your S15: Fuel Pump & Injectors.

Upgraded Fuel lines: For old cars and perhaps piece of mind, upgrading the fuel lines to a higher rating spec is a good idea. Last thing you want are them crumbling under pressure and squirting fuel everywhere.

Jerry Cans: because driving back and forth to a United/Caltex servo is fun said no one ever. Also a must for trackdays because no E85 compatible stations will be around. As an added bonus your ride will be lowered a few cm with extra weight… sick!

Tuner: your aftermarket ECU will need adjustment for the bigger injectors and then some dyno/road fine tuning to get the most out of the jungle juice. Just keep adding timing until she can’t take anymore!

E85: Find your local United/Caltex offering the fuel… duh.

Your new best friends… and you can choose how many too…

Months after converting Pearl there are still no regrets, my expectations have been blown away. I’ve definitely got no plans to go back to the boring old 98RON petrol anytime soon that’s for sure! Thanks Jay (who is also now on E85) for gently coercing me into making the change 😉

What are your thoughts? Have I tempted you enough to make the switch? Or have you already made the switch? Feel free to shoot any questions below!

About Flop

Open minded car enthusiast who appreciates most things on four wheels although JDM is where his heart lies. Wannabe racecar driver but having trouble fitting into his bucket seat since he's also a dedicated gym goer.

3 comments

Whilst ethanol is considered to be hydroscopic, you need to remember modern cars run sealed fuel tanks and only pull in air as required when the tank drains out. Also for those that fear the of the hydroscopic effects of ethanol then rest assure a little water in your motor won’t do any harm. Look at cars that run water/methanol injection or diesel trucks with pure water injection. Remember, even though ethanol is hydroscopic and you may have traces of water in your fuel, its’ not like running a pod filter into a pool of water and then trying to combust that.

I guess Sam the ethanol expert will be left eating everyone elses dust on track days, worrying about the evils of dihydrogen monoxide.

E85 is the best mod I’ve ever done to my R33. I gained 40kw peak power and over 60kw (and a massive amount of torque!) through the midrange, got rid of a knock issue that was ever present on 98RON and stopped warping exhaust/turbo manifolds from high EGT’s. The boost was also reduced from 20 to 18psi so actual gains are likely higher. So 320rwkw from a fully bolted stock RB25 running stock manifolds.

E85 cannot absorb moisture in a full, sealed jerry can and actually has a longer shelf life than PULP when stored in this manner. I always try to ensure the petrol tank is nearly empty when not in use which is pretty easy as the car only does track days and the tank is never filled.